On Wed, 2008-02-20 at 10:19 +0000, Charles Harpole wrote: > My factory bilt K3 , just out of the box, desensed nearly to zero rcve > with 1KW xmit on different band w. ant. 70 feet away.
70 feet is a tiny spacing in wave-length terms, depending on the antennas you could have several 10's of watts arriving at the K3 in this scenario. Before trying to operate multiple radios and multiple antennas you need first to evaluate how much interaction you have between ALL the various combinations. Then you need to take whatever steps are required to keep RF arriving at the other radios in damage inducing amounts. I am no expert multi-multi setups but I would be inclined to keep below 0.1w returned into 50 Ohms Another factor is wide-band phase noise on TX and amp generated noise. PA stages in radios and amplifiers tend to use high pass filters to reduce harmonic content, these will do little to clean up 'crud' below the TX frequency Be very careful in multi-TX setups you need to be careful about how you engineer things or you risk rig damage. If this is just for casual operating, adding interlocks to your band switching so that you can't inadvertently select combinations that are potentially risky might be a good idea > I want to know what filtering the VP6 guys are doing IN ADDITION to > turning on their K3s. 73Charles Lots of separation between stations on the same band, use of separate RX antennas separated by distance and polarisation, clean amps and probably a bunch of high quality band-pass filters too. 73 Brendan EI6IZ -- Don‘t complain. Nobody will understand. Or care. And certainly don‘t try to fix the situation yourself. It‘s dangerous. Leave it to a highly untrained, unqualified, expendable professional. _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
